It is known to provide a fuel tank in a vehicle to hold fuel to be used by an engine of the vehicle. It is also known to provide a fuel pump inside the fuel tank to pump fuel to the engine. Typically, the fuel pump includes a check valve to allow fuel to exit the fuel pump. Generally, a forward flow check valve consists of a checking or valve device, typically a plunger, such as a pintel having a seal, and a seat that when in contact form a leak proof seal. The pintel and seal are forced against the seat with a spring that provides the proper force to maintain pintel and seal to seat contact during no flow and low-pressure forward flow conditions. In automotive fuel pump applications, this force prevents flow from exiting the fuel tank when the vehicle fuel line is removed or severed.
Check valves in general, whether bullet nose, ball, or pintle and seal type, tend to be unstable in a fluid flow stream due to vortex shedding and eddy currents. This vortex shedding causes instability and oscillations of the checking or valve device, which in turn causes undesirable noise. The check valve of the pintle and seal type has a lower cost than other types of check valves, but is less aerodynamic than these other types of check valves. This makes it less stable in the flow stream and more likely to oscillate. It is also more difficult to contour the flow path downstream of the pintel and seal (because the return spring/retention features are upstream of the seat) to take advantage of an aerodynamic shape in eliminating oscillations.
Therefore, it is desirable to provide a check valve in a fuel pump for a vehicle that is more stable in a fluid flow stream. It is also desirable to provide a check valve for a fuel pump that eliminates oscillation of the pintel and reduces noise. It is further desirable to provide a check valve for a fuel pump at a relatively low cost. Therefore, there is a need in the art for a check valve that meets these desires.